28521288 has 64 divisors (see below), whose sum is σ = 82684800. Its totient is φ = 9092160.

The previous prime is 28521253. The next prime is 28521293. The reversal of 28521288 is 88212582.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2098 + ... + 7838.

It is an arithmetic number, because the mean of its divisors is an integer number (1291950).

Almost surely, 2^28521288 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28521288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41342400).

28521288 is an abundant number, since it is smaller than the sum of its proper divisors (54163512).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28521288 is a wasteful number, since it uses less digits than its factorization.

28521288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5779 (or 5769 counting only the distinct ones).

The product of its digits is 20480, while the sum is 36.

The square root of 28521288 is about 5340.5325577137. The cubic root of 28521288 is about 305.5317714061.

The spelling of 28521288 in words is "twenty-eight million, five hundred twenty-one thousand, two hundred eighty-eight".